overview of twi’s high · pdf filecopyright © twi ltd 2013 testing conducted...

Copyright © TWI Ltd 2013

Overview of TWI’s High Pressure

Hydrogen Testing Facility

2 day informational meeting

Sandia National Llaboratories

9 & 10 April 2013

Richard Pargeter & Chris Miller


Summary

• 2 dedicated vessels allow a variety of

mechanical tests to be performed in high

purity hydrogen gas at pressures up to

1000bar (14500psi)

• Testing can be conducted at elevated and

sub-zero temperatures

• Facility for pre-charging specimens with

hydrogen prior to testing

• Supporting, eg analytical, facilities.


450bar test vessel

• Atmospheric pressure to 450bar (6500psi)

• Ambient temperature to 100°C

– Heaters embedded in vessel wall

• Maximum tensile load: 100kN

• Maximum compressive load: 50kN

– (no pressure balance)

• Cyclic loading up to a maximum frequency

of 5Hz.


450bar Vessel

Locking

bolts

Pressure

gauge

External

load cell

Test

chamber

Vessel door

Servo-hydraulic

test machine


450bar Vessel

Internal load

cell

3-point bend

loading jig

DCPD

measurement

DC current

supply

Gas seals

SENB

specimen


1000bar vesel

• Atmospheric pressure to 1000bar

(14500psi)

– (seals not so good at low pressure)

• 85°C to -50°C

– Local specimen heating/cooling

• Maximum tensile and compressive load:

100kN (dynamically balanced)

• Cyclic loading up to a maximum frequency

of 5Hz.


1000bar Vessel - open

Internal load

cell

Lantern ring

Tensile

specimen

Cooling coil

External load cell

Locking

rods

Gas seal

External

vessel


-50°C tensile arrangement

Extensometer

Cooling block


1000bar Vessel - closed

Locking

rods

External

heat tracing

Pressure

gauge

Blast door

interlocks


Space fillers, 450bar

Removable

handles

Half block


Space fillers, 1000bar

From back

Front half

shell

Both half

shells


Control

• PID control – one button initiates full

purge sequence

• Pneumatic valves.


Pre-test sequence

• Specimen loaded into vessel

• Vessel & test cell closed and locked

• Nitrogen purges (3): 10 bar

• Hydrogen purges (8): 10 bar

• Quick fill to bottle pressure

• Booster on, pressurising the vessel

to test pressure

• Heating/cooling equilibriation

• Test initiated.

PID

controlled


Gas Supply

• 99.9999% purity Hydrogen

supplied in banks of 12

• Solenoid valves

• (Other gasses possible -

99.9999% purity He has been

used)

• Oxygen-free Nitrogen used for

purging

• Liquid nitrogen for cooling

• Air compressor for pneumatic

valves.


Gas Booster

• Boosts bottle

pressure

(typically 200bar

when full) to a

maximum of

1000bar

• Minimum bottle

pressure of

40bar required

for effective

operation.


Under great pressure

Under great pressure - TWI's Hydrogen test

facility - YouTube

http://www.youtube.com/watch?v=nRKxxHolDtI









Hydrogen Pre-charging

• Specimens exposed to high purity

hydrogen at up to 100bar (1450psi)

pressure and up to 500°C

• Used for Hastelloy 230, Alloy 783, Alloy

718, A286…


Hydrogen Pre-charging

Split-tube furnace

Alloy 625 vessel body

Cooled gas vent

Gas supply

Sealing flange

Thermocouple wire


Testing Conducted To-Date

• Tensile testing of round specimens

• Tensile testing of flat specimens

• Tensile testing of notched round

specimens

• Fatigue endurance testing of notched

round and flat tensile specimens

• Fracture toughness and fatigue crack

growth rate (FCGR) testing of single edge

notch bend (SENB) and surface notch

tension specimens.


Tensile Specimens


SENB Specimen in 3-point Bend


Future Development

• Development of tooling to accept a wider

range of specimen geometries; e.g.

compact tension specimens

• Development of technique for post-test

sampling and compositional analysis of

test gas.


Some issues


1000bar Initial lantern ring load cell trials

-3

-1

1

3

5

7

9

11

13

15

0 5 10 15 20 25 30

Lo

ad

, kN

Displacement, mm

Internal lantern ring

External load cell

Karma strain gauge

Normal strain gauge


0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

18.0

20.0

0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 20.0

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

18.0

20.0

0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 20.0

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

18.0

20.0

0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 20.0

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

18.0

20.0

0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 20.0

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

18.0

20.0

0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 20.0

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

18.0

20.0

0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 20.0

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

18.0

20.0

0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 20.0

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

18.0

20.0

0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 20.0

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

18.0

20.0

0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 20.0

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

18.0

20.0

0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 20.0

He (green) and H2, 400bar, -50°C

Extension, mm

20

0

Load,

kN

0 20


Current internal load cell

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

0.0 5.0 10.0 15.0 20.0 25.0 30.0

Lo

ad

, kN

Displacement, mm

5 hours


O-ring seal failure

• Post hot test (on decompression)

• Test not compromised

• Seals a consumable item.

450bar door seal


Seal spring failure


Thank you for your attention

Any questions?

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